Twenty two patients (44 eyes) with diabetes of the type I aged 18-60 were examined. Duration of diabetes--at least 10 years. Performed were routine ophthalmological, general medical and electrophysiological examinations (EOG, ERG, with registration of oscillatory potentials, visual evoked potentials). It was evidenced that the most accurate method demonstrating the disturbances of the retinal function--independently of the visual acuity, fundus changes and other signs and complications--are the oscillatory potentials. Evoked visual potentials enable us in a majority of cases to evidence the central and subclinical disturbances of the optic nerve.